Automatic cut-out for electric irons



April 14, 1925. 1,533,233

L. N. CRICHTON 7 AUTOMATIC CUT-OUT FOR ELECTRIC IRONS Filed Sept. 25, 1921 aw 25 24 8 BY 353M e ATTORNEY Patented Apr. 14,

U ITED-' STATES IQPATENIT oFFIcE.

LESLIE GRICHTON, 0F EDGEWOOD, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

AurroMAmcoU'r-owr non ELEGJTRIC mons.

, Application filed September T 0 all whom it may concern.

Be it known that I, LESLIE N. CRIcH'roN a citizen of the United States, and a resident of Edgewood, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Automatic Cut-Outs for Electric Irons, of which the following is a specification. M

My invention relates to electrically-heated devices and particularly to electrically heated flat irons, and it has for its object to provide a relatively simple. and inexpensive circuit-controlling means for an electrically-heated iron.

In practising my invention, I provide atubular member of suitable insulating material and of substantially S or V-shape, with electric circuit-terminals and with a body of mercury to engage both terminals, under normal operating conditions, to conduct the 'main-line current therethrough. One end iron comprising a device embodying my invention;

Fig. 2 is a top plan view, with certain portions in section, of an iron comprising a device embodying my invention;

- Fig. 3 is a View, in longitudinal section, of a device embodying my invention, shown in its normal operating position;

Fig. 4 is a view, in longitudinal section, of

- the device illustrated in Fig. 3, shown in a tilted position, and

Fig. 5 is a partially sectional view of a portion of an electric iron in which is lo cated amodified form of the device embodying my invention.

An electric iron 5' comprises a working member or sole plate 6, a top plate 7 and an electric'heating element 8 clamped therebctween by a plurality of bolts (not shown), these members constitutin what may be called the body portion. A hood or cover member 9 maybe clamped against the working member 6 by means of a bolt 10. Two

2a, 1921. Serial No. 562,631.

handle straps 11 are secured, at their lower ends, against the hood'9 by means of rivets 12,. and support, at their upper ends, a

handle 13.

The heating element 8, which may be of any suitable or desired construction usually employed in such devices, comprises a resistor member 15 that is provided with suitable terminal straps 14;. Contact-terminals 16 are suitably secured to the terminal straps 14 and extend outwardly through an opening 17 in the rear portion of the hood 9, being maintained in proper position relatively thereto by an insulating member 18 through which they extend. The ends of the resistor 15 may be secured to the terminal straps 14 by means of bolts 19. r

A longitudinally extending groove 20 is I provided at substantiall the middle of the width ofthe top plate and extendin inwardly from the rear edge thereof. wo co-operating insulating members 21 are located in'the groove 20, and a circuit-interrupting device 22 is clamped tightly therebetween, suitable groovesbeing provided in the opposing faces of the members 21- to permit of locating the member 22 therebe-.

tween.

' The device 22 comprises a tubular member of quartz or glass bent to substantially S- form, the legs of which are of different lengths. The shorter leg of the device 22 terminates in an expanded chamber 23. A small quantity of mercury 24- is placed inside of the device 22, and the ends of thelonger leg are provided with inwardly pro- -]ecting circult terminals 25.. The terminals 25 are connected 1n series-circuit relation to the resistor 15 by suitable conductors 26 and 27. The diameter of the tube within which the mercury 24 is placed is larger than that of the ordinary capillary tube, as it is not desired to cause the mercury to be vaporized by the heat generatedby the current traversing the column of mercury. The device 22 may be evacuated or it may have an inert gas containedtherem'.

The device 22 is so located with reference to the body of the iron that-the longer leg is substantially horizontal during the operation of the iron. As the boiling point of mercury is substantially 460 F it is only necessary to so position the circuit-interrupting device 22- with reference to the top plate approximately 500 F.

25 in the corresponding leg.

that substantially all of the mercury con tained therein shall be vaporized when the temperature of the working member 6 exceeds a predetermined value, which may be When the temperature of the working surface of the iron exceeds a predetermined value, the mercury in the device 22 is vaporized and flows through I the tortuous passage into the condensing 10 chamber-23 whereby the circuit through the resistor is interrupted. After the mercury has. been re-condensed in the chamber 23, it is only necessary to tilt the iron forwards, to permit the condensed mercury to 15 again flow into the portion of the tubular device 22 between the electric circuit terminals 25, thereby re-establishing the circuit through the resistor 15.

In Fig. 5 is illustrated a modified form 2010f container comprising 'a. glass or quartz 80 vice 28 is slightly enlarged to constitute a condensing chamber. The action of the modified form of my device is substantially the same as that hereinbefore described in connection with the device 22 and it may use either a vacuum or an inert'gas as may be desired.

It is possible to use the device 22 or the device 28 as a manually operated circuit-interrupting device whenever desired, by sim- 4 ply tilting the iron backwards from its normal position, thus permitting the mercury to flow to the condensing chamber and thereby interrupt the circuit. The method of re-establishing the circuit is, of course, substantially the same as hereinbefore described after the mercuryhas been caused to vaporize by the heat of the iron.

It may be noted that the device embodying my invention provides a relatively simple, inexpensive and easily installed device under the thermal control of the heating element to interrupt the circuit through the resistor of an electric iron." The device may also be employed for manually interrupte.-

ing and closing the circuit whenever sired bv the operator and permitted by the thermal conditions of the iron.

Various modifications may be made in the device embodying 'niy invention without dcparting from the spirit thereof, lil-ll(l I desire that only such limitations shall be placed thereon as are imposed by the prior art or are specifically .set forth in the ap pended claims.

. I claim as my invention:

1. In an electrically heated portable device, the combination with a heating element, of a circuit cont-roller comprising a column of a volatilizable conducting fluid connected in series-circuit and heat-receiving relation to said heating element for interrupting the circuit therethrough when said fluid column is volatilized by the heat of said heatin element and for permitting the re-establi ling of the circuit therethrough by tilting the device through an angle of substantially 2. In a portable electrically heated device, the combination with a heating element, of a circuit controller comprising an insulating tubular container located in heatreceiving relation to said heating element, a column of a volatiliz-able conducting fluid in said container connected in series-circuit relation to said heating element for interrupting the circuit therethrough when the device is tilted an angle of substantially 90 and when said fluid column is partly vollatilized by the heat of said heating element.

3. An-electrically heated iron comprising a means for interrupting the circuit therethrough upon the occurrence of a predetermined temperature therein and for permitting the re-establishing of the circuit by turning the iron on its transverse axis.

4. In an electrically heated iron, in combination, a body portion, and a circuit-interrupting moans located in said body portion com )rising a container and a volatilizable cont ucting fluid in said container for interrupting the circuit upon the occurrence of a predetermined temperature in said body portion and for reclosing the circuit by a turning movement of said iron on its transverse axis.

In testimony whereof, I have hereunto subscribed my name this l9th day of September, 1921.

LESLIE N. CRICHTON.

Inn 

